This relates generally to electronic devices with displays, and, more particularly, to displays with backlights.
Electronic devices such as computers and cellular telephones have displays. Some displays such as plasma displays and organic light-emitting diode displays have arrays of pixels that generate light. In displays of this type, backlighting is not necessary because the pixels themselves produce light. Other displays contain passive pixels that can alter the amount of light that is transmitted through the display to display information for a user. Passive pixels do not produce light themselves, so it is often desirable to provide backlight for a display with passive pixels.
In a typical backlight assembly for a display, a light guide plate is used to distribute backlight generated by a light source such as a light-emitting diode light source. Optical films may be placed on top of the light guide plate. A reflector may be formed under the light guide plate to improve backlight efficiency.
In conventional backlight assemblies, a large number of optical films are used to collimate and diffuse the light that is emitted from the light guide plate. For example, four or more films may be required to manipulate the backlight. This may result in the backlight assembly having a larger than desirable thickness.
It would therefore be desirable to be able to provide displays with improved backlights.